2 * a64 video encoder - multicolor modes
3 * Copyright (c) 2009 Tobias Bindhammer
5 * This file is part of Libav.
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
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13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * a64 video encoder - multicolor modes
28 #include "a64colors.h"
29 #include "a64tables.h"
32 #include "libavutil/common.h"
33 #include "libavutil/intreadwrite.h"
36 #define CHARSET_CHARS 256
38 #define CROP_SCREENS 1
41 static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
43 /* other possible gradients - to be tested */
44 //static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
45 //static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
47 static void to_meta_with_crop(AVCodecContext *avctx, AVFrame *p, int *dest)
49 int blockx, blocky, x, y;
51 int height = FFMIN(avctx->height, C64YRES);
52 int width = FFMIN(avctx->width , C64XRES);
53 uint8_t *src = p->data[0];
55 for (blocky = 0; blocky < C64YRES; blocky += 8) {
56 for (blockx = 0; blockx < C64XRES; blockx += 8) {
57 for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
58 for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
59 if(x < width && y < height) {
60 /* build average over 2 pixels */
61 luma = (src[(x + 0 + y * p->linesize[0])] +
62 src[(x + 1 + y * p->linesize[0])]) / 2;
63 /* write blocks as linear data now so they are suitable for elbg */
73 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
76 A64Context *c = avctx->priv_data;
81 int lowdiff, highdiff;
82 int *best_cb = c->mc_best_cb;
83 static uint8_t index1[256];
84 static uint8_t index2[256];
85 static uint8_t dither[256];
89 /* generate lookup-tables for dither and index before looping */
91 for (a=0; a < 256; a++) {
92 if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
93 distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
94 for(b = 0; b <= distance; b++) {
95 dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
99 if(i >= c->mc_pal_size - 1) dither[a] = 0;
101 index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
104 /* and render charset */
105 for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
108 for (y = 0; y < 8; y++) {
110 for (x = 0; x < 4; x++) {
111 pix = best_cb[y * 4 + x];
113 /* accumulate error for brightest/darkest color */
114 if (index1[pix] >= 3)
115 highdiff += pix - c->mc_luma_vals[3];
117 lowdiff += c->mc_luma_vals[1] - pix;
123 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
124 row1 |= 3-(index2[pix] & 3);
126 row1 |= 3-(index1[pix] & 3);
128 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
129 row2 |= 3-(index2[pix] & 3);
131 row2 |= 3-(index1[pix] & 3);
134 if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
135 row1 |= 3-(index2[pix] & 3);
137 row1 |= 3-(index1[pix] & 3);
140 charset[y+0x000] = row1;
141 if (INTERLACED) charset[y+0x800] = row2;
143 /* do we need to adjust pixels? */
144 if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
145 if (lowdiff > highdiff) {
146 for (x = 0; x < 32; x++)
147 best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
149 for (x = 0; x < 32; x++)
150 best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
152 charpos--; /* redo now adjusted char */
153 /* no adjustment needed, all fine */
155 /* advance pointers */
159 /* remember colorram value */
160 colrammap[charpos] = (highdiff > 0);
165 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
167 A64Context *c = avctx->priv_data;
168 av_frame_free(&avctx->coded_frame);
169 av_free(c->mc_meta_charset);
170 av_free(c->mc_best_cb);
171 av_free(c->mc_charset);
172 av_free(c->mc_charmap);
173 av_free(c->mc_colram);
177 static av_cold int a64multi_encode_init(AVCodecContext *avctx)
179 A64Context *c = avctx->priv_data;
181 av_lfg_init(&c->randctx, 1);
183 if (avctx->global_quality < 1) {
186 c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
189 av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
191 c->mc_frame_counter = 0;
192 c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
193 c->mc_pal_size = 4 + c->mc_use_5col;
195 /* precalc luma values for later use */
196 for (a = 0; a < c->mc_pal_size; a++) {
197 c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
198 a64_palette[mc_colors[a]][1] * 0.59 +
199 a64_palette[mc_colors[a]][2] * 0.11;
202 if (!(c->mc_meta_charset = av_malloc(32000 * c->mc_lifetime * sizeof(int))) ||
203 !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
204 !(c->mc_charmap = av_mallocz(1000 * c->mc_lifetime * sizeof(int))) ||
205 !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t))) ||
206 !(c->mc_charset = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
207 av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
208 return AVERROR(ENOMEM);
211 /* set up extradata */
212 if (!(avctx->extradata = av_mallocz(8 * 4 + FF_INPUT_BUFFER_PADDING_SIZE))) {
213 av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
214 return AVERROR(ENOMEM);
216 avctx->extradata_size = 8 * 4;
217 AV_WB32(avctx->extradata, c->mc_lifetime);
218 AV_WB32(avctx->extradata + 16, INTERLACED);
220 avctx->coded_frame = av_frame_alloc();
221 if (!avctx->coded_frame) {
222 a64multi_close_encoder(avctx);
223 return AVERROR(ENOMEM);
226 avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
227 avctx->coded_frame->key_frame = 1;
228 if (!avctx->codec_tag)
229 avctx->codec_tag = AV_RL32("a64m");
231 c->next_pts = AV_NOPTS_VALUE;
236 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
240 /* only needs to be done in 5col mode */
241 /* XXX could be squeezed to 0x80 bytes */
242 for (a = 0; a < 256; a++) {
243 temp = colram[charmap[a + 0x000]] << 0;
244 temp |= colram[charmap[a + 0x100]] << 1;
245 temp |= colram[charmap[a + 0x200]] << 2;
246 if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
251 static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
252 const AVFrame *pict, int *got_packet)
254 A64Context *c = avctx->priv_data;
255 AVFrame *const p = avctx->coded_frame;
265 int *charmap = c->mc_charmap;
266 uint8_t *colram = c->mc_colram;
267 uint8_t *charset = c->mc_charset;
268 int *meta = c->mc_meta_charset;
269 int *best_cb = c->mc_best_cb;
271 int charset_size = 0x800 * (INTERLACED + 1);
272 int colram_size = 0x100 * c->mc_use_5col;
276 b_height = FFMIN(avctx->height,C64YRES) >> 3;
277 b_width = FFMIN(avctx->width ,C64XRES) >> 3;
278 screen_size = b_width * b_height;
280 b_height = C64YRES >> 3;
281 b_width = C64XRES >> 3;
285 /* no data, means end encoding asap */
287 /* all done, end encoding */
288 if (!c->mc_lifetime) return 0;
289 /* no more frames in queue, prepare to flush remaining frames */
290 if (!c->mc_frame_counter) {
293 /* still frames in queue so limit lifetime to remaining frames */
294 else c->mc_lifetime = c->mc_frame_counter;
295 /* still new data available */
297 /* fill up mc_meta_charset with data until lifetime exceeds */
298 if (c->mc_frame_counter < c->mc_lifetime) {
300 p->pict_type = AV_PICTURE_TYPE_I;
302 to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
303 c->mc_frame_counter++;
304 if (c->next_pts == AV_NOPTS_VALUE)
305 c->next_pts = pict->pts;
306 /* lifetime is not reached so wait for next frame first */
311 /* lifetime reached so now convert X frames at once */
312 if (c->mc_frame_counter == c->mc_lifetime) {
314 /* any frames to encode? */
315 if (c->mc_lifetime) {
316 req_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
317 if ((ret = ff_alloc_packet(pkt, req_size)) < 0) {
318 av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", req_size);
323 /* calc optimal new charset + charmaps */
324 ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
325 ff_do_elbg (meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
327 /* create colorram map and a c64 readable charset */
328 render_charset(avctx, charset, colram);
330 /* copy charset to buf */
331 memcpy(buf, charset, charset_size);
333 /* advance pointers */
335 charset += charset_size;
338 /* write x frames to buf */
339 for (frame = 0; frame < c->mc_lifetime; frame++) {
340 /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
341 for (y = 0; y < b_height; y++) {
342 for (x = 0; x < b_width; x++) {
343 buf[y * b_width + x] = charmap[y * b_width + x];
346 /* advance pointers */
348 req_size += screen_size;
350 /* compress and copy colram to buf */
351 if (c->mc_use_5col) {
352 a64_compress_colram(buf, charmap, colram);
353 /* advance pointers */
355 req_size += colram_size;
358 /* advance to next charmap */
362 AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
363 AV_WB32(avctx->extradata + 8, charset_size);
364 AV_WB32(avctx->extradata + 12, screen_size + colram_size);
367 c->mc_frame_counter = 0;
369 pkt->pts = pkt->dts = c->next_pts;
370 c->next_pts = AV_NOPTS_VALUE;
372 pkt->size = req_size;
373 pkt->flags |= AV_PKT_FLAG_KEY;
374 *got_packet = !!req_size;
379 AVCodec ff_a64multi_encoder = {
381 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
382 .type = AVMEDIA_TYPE_VIDEO,
383 .id = AV_CODEC_ID_A64_MULTI,
384 .priv_data_size = sizeof(A64Context),
385 .init = a64multi_encode_init,
386 .encode2 = a64multi_encode_frame,
387 .close = a64multi_close_encoder,
388 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
389 .capabilities = CODEC_CAP_DELAY,
392 AVCodec ff_a64multi5_encoder = {
394 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
395 .type = AVMEDIA_TYPE_VIDEO,
396 .id = AV_CODEC_ID_A64_MULTI5,
397 .priv_data_size = sizeof(A64Context),
398 .init = a64multi_encode_init,
399 .encode2 = a64multi_encode_frame,
400 .close = a64multi_close_encoder,
401 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
402 .capabilities = CODEC_CAP_DELAY,